Public consultations are officially underway regarding the likely very messy future of Saint Catherine Street West.
The public is being invited to share their thoughts online at saintecath.ca. And city officials will be out on the streets over the summer - including during the July 12-13 street sale - to inform the public and answer questions. Public forums will also be held in the summer and fall.
The work will involve replacing the city's aging sewer and water infrastructure, some of it dating back over a century.
Renovating the downtown artery will be done in two phases.
The first chunk to go under the knife will be the stretch between Mansfield and Bleury, and include the area south of Phillips Square.
That's slated to begin in the spring of 2016 and cost between $80-95-million.
The second stretch runs from Atwater to Mansfield. That will begin in 2019. No price tag has been attached.
Coderre said about half of the first phase will be completed by the time Montreal celebrates its 375th anniversary. Construction will be halted for the duration of the celebrations and resume once they are completed.
He added that there will be no tramway, citing its prohibitive cost.